Last night David Cameron, Prime Minster and Conservative Party leader, announced that he would not take part in the proposed leadership debates this year's UK General Election. Or rather, he wouldn't unless the Green Party was also invited alongside Labour, Lib Dems and Ukip. This was after Ofcom, the media regulator, suggested that the Greens were not a major party, but that Ukip and the Lib Dems were.
In the petty tactical thinking that so dominates thinking amongst Westminster's political elite, it is easy to understand Mr Cameron's move. Two birds can be killed with one stone. First the Greens have emerged as a thorn in Labour's side, as they are promoting an unambiguously leftist policy platform, and also attract Lib Dem defectors, who are central to Labour's electoral strategy. They do not trouble potential Tory voters though. The second aim is that Mr Cameron is not much interested in taking part in the debates anyway. These debates were an innovation in 2010, and greatly expanded political engagement, especially amongst younger voters. But the conventional Tory wisdom were that they were a mistake, assisting the Lib Dems at their expense. And this time Mr Cameron has more to lose than gain. Especially if Labour's Ed Miliband turns out to be much less of clump than the Tories are portraying him to be.
The announcement was also an opportunity for Mr Cameron to sneer at his coalition partners, the Lib Dems. His claim for the Greens to be a major party was that the Greens beat the Lib Dems in last year's European elections. But the Lib Dems have 57 seats and record in government to defend, compared to the Greens' single seat. Mr Cameron's voice dripped in sneering condescension in a way that only upper class Brits can do.
But it's a strategic mistake, for all that. Along with the Labour party, the Tories claim that they are the only parties that matter in the election. Electors must choose between these two; everybody else is a waste of time. They dream that a few days before the election, electors will come to their senses and return to voting for the two establishment parties. But now Mr Cameron has painted a picture of a multiparty leadership debate, rather like those we saw on the Danish TV series Borgen. Yet this idea is toxic to the two-party vision. If he had said that he would only debate with Mr Miliband, it would have had strategic value.
All of which reinforces a general sense of Mr Cameron's weakness as a prime minister. Too clever for his own good. Ever after gaining a tactical advantage, but with no idea of his, or his country's, strategic interests.